Malicious PDF — malware analysis report

Static analysis result for SHA-256 218461e1e2c4cc33…

MALICIOUS

PDF

125.7 KB Created: 2021-09-07 03:49:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 43c345c7209ebe2816a177a2d566b4a9 SHA-1: d0e82ee81f5dd3eeb295eb781b1e5233d59cf560 SHA-256: 218461e1e2c4cc33816f7bdaee9877a5b57bfbfcd2681aae5d4151f357c065f4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external links, many pointing to other PDF files hosted on various domains, indicating a link farm or redirection scheme. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://himanshikitchen.info/viking1/uploads/files/fizovutuzine.pdf In PDF document text
    • http://veterina-hrib.cz/user-uploads/files/39467443793.pdfIn PDF document text
    • http://www.ecvbrass.ch/user/web/file/fozixenefenedazorakus.pdfIn PDF document text
    • http://nikolalepojevic5.com/multimedia/file/1961716689.pdfIn PDF document text
    • http://uzks.hr/upload/datoteke/9498256815.pdfIn PDF document text
    • http://dichvuhieuchuan.com/upload/files/72310728186.pdfIn PDF document text
    • https://kurtoglumob.com/upload/file/86103803212.pdfIn PDF document text
    • http://nanoscopy.ru/uploads/files/80843566277.pdfIn PDF document text
    • http://backyardreleaf.ca/clients/6/6a/6a4eaaf8452764cb6fc14c9064ed0c71/File/11485003074.pdfIn PDF document text
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/jukafasisekuguli.pdfIn PDF document text
    • http://omni-links.com/images/blog//file/weparewunok.pdfIn PDF document text
    • http://spamsmsgiare.com/media/ftp/file/25365626491.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/42742c1cf50dd70a23d35ee0b1f87e44/46914158992.pdfIn PDF document text
    • http://tuanayapim.com/rsm/files/73869046705.pdfIn PDF document text
    • http://navigator-nsk.ru/userfiles/file/72849454041.pdfIn PDF document text
    • http://w-f-l.de/user_img/file/34501708585.pdfIn PDF document text
    • http://onlinemidias.com/ckfinder/userfiles/files/wizuramopu.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606fc0d9b893f---laderubobejifa.pdfIn PDF document text
    • http://akinmedical.com/uploads/file/didubutafuz.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/hvo0cttf0i71rtkivv3amg769e/wutosemeraw.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/mafudukibugokipozida.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=eksploitasi+politik+dan+ekonomi+belanda+di+indonesia+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001867d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1867D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00019e8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19E8F 18972 bytes
SHA-256: 81b9f7a5c2d7ca1d093b16f1cf493a32c63c525abf4f9e4010f4884c7e5efc08
font_02_sfnt_off0001d03d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D03D 10772 bytes
SHA-256: dbdfa90f68f8d34e2abe307e509e407a938ba871abe76cb9c4b9b93fa53157da